1. Field of the Invention
This invention relates to a liquid container sealing construction.
2. Description of the Prior Art
Numerous container structures shaped like a cylinder, a cone or a prism have been developed and used over the past years for containing therein liquids having a relatively high pH and a high permeability, such as milk, juice, oil, liquor, cleanser, or lactic acid beverage. The container bodies have been usually constucted of paper coated on its inner surface with a liquid-tight material. The top and bottom open ends of the liquid container are sealed by suitable end closure members. Various attempts have been proposed to prevent leakage through a region where the end closure members are sealed to the container body. One such effort is to bond a flanged end closure to the inside wall of container body with an adhesive, as shown in FIG. 9A of the accompanying drawings. According to another proposal as shown in FIG. 9B, a marginal extension of the container body is turned inwardly over the joined flange of the end closure member like a seam of a can to provide a more rigid joining construction. A still further prior sealing structure is shown in FIG. 9C and comprises a flat end closure member heat sealed or otherwise coupled to a flange extending radially outwardly of the container body.
The sealing construction illustrated in FIG. 9B however requires a tedious and time consuming process and hence, has poor machinability. The construction shown in FIG. 9C involves a complicated procedure of forming the flange on the container body. Furthermore, the latter construction has the drawback that the projecting flange of the container is unsightly and requires a wide floor space when a multiplicity of containers are to be transferred or stored.
It has been heretofore found that the container sealing construction of FIG. 9A is most preferable from the standpoint of machinability. A prior art process for manufacturing this container sealing construction, however, cannot be carried out economically because completely liquid-tight sealing construction are unable to be produced at is mass production rate.